Not his fault the defense is completely devoid of talent. You can thank Hugh Freeze and the NCAA for that.
It's not entirely his fault at the talent level, although he's recruited the last couple of years.
He is a terrible coach, though. Very unimpressive and doesn't have a clue. A decent defensive coordinator with crappy talent would have them in the right alignments and checks, but see them get trucked and run over. Ole Miss gets trucked and run over....but they are also disorganized, confused, they over pursue, and are out of position all over the field. He is directly responsible for that.
I hope they keep him at least as long as they keep the landshark mascot.